The present invention relates to rotation sensors. More particularly, the invention relates to rotation sensors that detect wheel rotation, from which the speed of a vehicle can be determined.
Some rotation sensors include components (often targets) in the wheel or wheel rim and other components (that process information from the target) that are located on the chassis. The rotation sensors determine the time it takes for targets to pass the sensor. In some technologies, the angular separation of the targets and the elapsed time is used to determine the speed of the wheel.